Shrouded tube compressor



y 1, 1956 F. BURGER SHROUDED TUBE COMPRESSOR Filed Oct. 25, 1954 INVENTOR.

United States PatentO 6 Claims. (Cl. 222-97) This invention relates to a new and improved apparatus for expelling the contents of containers of the collapsible tube variety.

Many varied types of apparatus for expelling or removing the contents of such tubes have been described and suggested at various times'in the past. While generally operable in more or less satisfactory degree, the various devices heretofore proposed have suffered from a variety of disadvantages.

In some of the prior art devices the tube has been compressed progressively between a pair of rolls, and driven between the rolls by the force of frictional engagement between the rolls and the walls of the tube. This type is disadvantageousin that the frictional force is not always sufficient to prevent slippage, especially on glossy-painted tubes, or when the pasty contents of the tube is especially viscous and stiff. This difiiculty has been overcome in some adaptations by providing a knurled or other uneven surfacelon the rollers, but this type of roll tends to leave pockets in the tube, so that it is not completely emptied, and more important, has a 2 evacuation of the tube and speed and efliciency of the apparatus were not of particular importance.

In recent years, however, the use of collapsible tubes has undergone considerable development, and one of the most commercially important aspects of this development is the practice of filling the tubes with precisely measured quantities of material. An example of the application of this method is in the paint industry. The paint dealer is now supplied with a base stock of white paint and an assortment of tubes containing measured quantities of oil colors. Upon receipt of an order for a given color, he then is able to select the proper size tube of the appropriate oil color, empty it completely into a specified quantity of the base stock, and mix, to achieve a precise and reproducible colored paint. The advantages of such a system are enormous as to the savings in storage space and inventory investment over the old system of stocking a complete supply of ready-to-use paint in all shades. This development has, however, created a definite need for a simple positively-acting device which will empty the color tube substantially quantitatively.

It is therefore an obect of this invention to provide an improved apparatus for emptying collapsible tubes. A further object is to provide such a device which will not tear or distort the tube in use. An additional object is to provide a tube collapsing device of improved simplicity and efficiency in operation. These and other objectswill become apparent as this invention is hereinafter more, fully described and claimed.

In its broadest aspects, this invention contemplates a tube compressingdevice of the type comprising a traction pronounced tendency to tear the tube open, thus defeat- I ing the whole purpose of the operation.

Other prior art devices also provided compression members in the form of rolls or the like, coupled with traction means of various kinds designed to clamp on the bottom end of the tube and pull it between the rolls or other compression members. This class of devices represents an improvement over those of the type first mentioned, but devices of this class were in general of such construction that the tension created in operation tended to pull the conventional channel-shaped closure member off the bottom of the tube, with generally disastrons consequences.

A third type of device in common use was the key type. This was perhaps the least desirable of all the prior devices, but is noted here because it bears certain superficial similarities to the device of the present invention, and for the purpose of illustrating the distinguishing features, which are hereinafter pointed out.

In the key-type apparatus, a slotted spindle or key is provided, which is adapted to receive the bottom end of the tube to be emptied, by inserting said end in the slot provided. The tube is then emptied by winding it up upon itself, using the key as an axis and torsion transmitter. The most serious disadvantages of this apparatus were two; in the first place, each successive revolution of the tube introduced its own share of irregularity and distortion, with the result that the tube was left in a lumpy, twisted condition, and only partially evacuated. In the second place, the whole tube had to be unwound and straightened out again before the device could be reused.

These difficulties, or some of them, were formerly of little significance, since the tubes were used in connection with inexpensive materials, or with materials used only on a small scale, or for other reasons complete rollhaving a slot adapted to receive the bottom closure of a conventional collapsible tube, said device having a shroud surrounding said traction roll throughout the greater part of its periphery, said shroud operative to hinder the radial egress of said bottom closure from said slot. This invention further contemplates a device of the type described wherein said traction roll is of such large circumference that said tube may be stretched thereon without substantial overlapping.

In a particularly desirable embodiment, this invention contemplates a tube compressor of the type described wherein said traction roll coacts with a compression roll to expel the-contents of said tube by compressing the same between saidtwo rolls.

In, another particularlyde'sirable embodiment, this invention contemplates a tube compressor having a traction roll as above described, said roll being fitted with a stop operative to prevent its rotation beyond 360 and a plurality of slots positioned at various points around the circumference of said roll to accommodate a variety of tube sizes.

Referring now to the figures, Fig. 1 shows a front view of an embodiment of the present invention, wherein 11 is the traction roll, mostly concealed by the shroud 12, the shroud having an aperture or window 13 through which the lower end of a collapsible tube may be inserted in slot 14. Means for rotating the traction roll within the shroud are represented by wing nut 15.

Fig. 2 is a cross-section taken along line 2-2 of Fig. 1, showing the manner in which the slot is undercut so as to hinder radial egress of the lower or clasp end of a collapsible tube. Also shown in this view is a thickened portion 16 of shroud 12, supplied to provide additional rigidity at the point of greatest strain on the shroud.

Fig. 3 is a view similar to Fig. 2, showing a modified embodiment of the invention provided with a compression roll 17, in place of the thickened portion of the shroud. Also shown in Fig. 3 are several slots 14a, 14b, 14c, 14d, designed to accommodate various sizes of tube. When several slots are provided in this manner, there is also provided a stop (not shown in Fig. 3), which limits the rotation of the traction roll within the shroud in such wise that, when a tube is inserted in the proper slot and the roll is rotated, the rotation will be automatically halted when the mouth of the tube is near the window of the shroud. With such arrangement, it is impossible to accidentally turn the traction roll too far and draw the whole tube into the annular space between the compression roll and the shroud.

Fig. 4 is an end view of the device of Fig. 3, showing one convenient type of stop means, in the form of lug 1S projecting inwardly from the lip of shroud 12, and pin 19 projecting out of the end of traction roll 11. In operation, the roll may rotate clockwise almost 360 from the position shown, and it consequently follows that slot 14a, which is shown as being aligned with window 13 is the slot designed for accommodation of the largest contemplated tube size. Slot 14b is for a somewhat smaller size tube, and if the roll is rotated clockwise to align slot 14b with the window, pin 19 will already have completed a portion of its possible travel, so that less rotation will be possible before it strikes lug 18. The position of slot 14b is so selected that the amount of travel permitted is just sufficient to bring the mouth of the tube up to the window and prevent its being drawn inside. Slots 14c and 14d are for still smaller tube sizes as will be apparent on inspection.

The device of the present invention possesses greatly improved efficiency and ease of operation over the devices of the prior art. In particular it provides assurance against incomplete exhausting of the contents of the tube, and gives uniformity of operation from tube to tube.

In the preferred embodiment, appropriate provision is made for accommodation of tubes of various sizes, and assurance that the operation will be stopped at the same point time after time, giving complete uniformity of operation and protection against the possibility of drawing the entire tube into the interior of the device.

It is a particularly advantageous feature of the present device, that the shroud surrounds substantially the entire circumference of the traction roll, and that the clearance between the traction roll and the shroud-i. e. the annular space into which the exhausted tube is drawnis small. With such arrangement, the empty tube can be removed from the device as simply as it is inserted, merely be reversing the direction of rotation of the roll. No prior device has shown this combination of features, it being necessary in most cases to remove the traction roll altogether in order to free it of the spent tube, and

then to reassemble the device before another tube could be inserted.

While this invention has been described with reference to certain embodiments and illustrated in certain specific forms, these are to be understood as illustrative only, and the invention is not to be limited, except as set forth in the following claims.

I claim:

1. A tube compressing device of the type comprising a traction roll having a slot adapted to receive the bottom closure of a conventional collapsible tube, said device having a shroud closely surrounding said traction roll throughout the greater part of its periphery, said shroud operative to hinder radial egressof said bottom closure from said slot.

2. A device according to claim 1, wherein the circumference of said roll is at least as large as the length of said tube.

3. A device according to claim 1, comprising a compression roll associated with said traction roll, said two rolls acting to expel the contents of said tube by compressing the same between them.

4. A tube compressing device of the type comprising a traction roll having a slot adapted to receive the bottom closure of a conventional collapsible tube, said device having a shroud surrounding said traction roll throughout the greater part of its periphery, said shroud operative to hinder radial egress of said bottom closure from said slot, and rotation-limiting means operative to prevent rotation of said traction roll beyond 360.

5. A device according to claim 4, having a plurality of slots positioned at spaced points around the circum ference of said roll to accommodate a variety of tube sizes.

6. A tube-compressing device of the type comprising a traction roll having a slot adapted to receive the bottom closure of a conventional collapsible tube, said device having a shroud substantially completely encasing the cylindrical face of said traction roll, said shroud being operative to hinder radial egress of said bottom closure from said sot, the annular space between said traction roll and said shroud being not greatly in excess of the thickness of a flattened empty tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,935,457 McGuire Nov. 14, 1933 2,536,867 Barnett Jan. 2, 1951 2,599,805 Beijbom June 10, 1952 

